In the HVAC field, I sometimes see 240v ,30 amp gfci plugs on ptac a/c units (thru wall like you would see in a motel). I have a 20 amp that I was able to source from a dead unit. Did you already check ebay/amazon?
Awesome job, blood sweat and tears consumed are evident (and $$$)! Just some advise on the HVAC side. I built my own glycol chiller using a 1/3hp condenser and 3 gallons of glycol. Perfect for chilling wort from 120 to pitching temp and maintaining 14 gal brewtech fermenter. May I suggest you...
Not nearly on par with my ther#$pen, but also 90% cheaper. If Inkbird wants to really get in the game, make them IP67 waterproof (And the dual probe Bluetooth grill thermometers too....Please!) On my 3rd By probe because it seems to be the 1 item left on the grill overnight, then it rains!
I have a speed controller intended for hood exhausts and played with it for a little while. my experience was that the pump could only be slowed 10-15% and would begin to stall out. In the end my realization was a need for more not less. A ball valve on the out side proved to be the best...
Heat is usually a result of undersized wiring. And the fact that its 2 years old now supports the idea. Are you feeding the 50 amp spa panel with #6 wire? If its #8 or 10 there is your problem. you can change the breaker, but 2 years down the line may see the same issues.
Very nice hood, unfortunately preventing condensation on the hood is like trying to stop a cold beer from sweating on a hot day! I have sprayed the inside of hoods with rubber sealant and had success to a limited degree. That said fresh air is key.
Thinking about your project, i stumbled across a youtube video where a guy made "air conditioning" from a table fan. This idea may apply to what you are trying to do. Check this out when you get a chance. https://www.youtube.com/watch?v=5NuvzWaBulw . If you had say a 5 gal cold tank and loop...
Can get expensive quick, pumps fans coil etc. consider a used window a/c. Many others have modded at minimal cost. A decent glycol pump will likely start at $150. that could get you and a/c, temp controller, and your next recipe.